Re: large temp files created by mysql

2012-05-24 Thread Luis Daniel Lucio Quiroz
I got a solution maybe step 1: mysql explain select * from users; ++-+---+--+---+--+-+--+--+---+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |

Re: Need help for performance tuning with Mysql

2012-05-24 Thread Yu Watanabe
Alex Thank you for the advice. Probably, we will put index (key) on both columns. Thanks, Yu Alex Schaft さんは書きました: On 2012/05/24 07:37, Alex Schaft wrote: You are selecting a record based on the value of data_id and thold_enabled, but don't have an index on either? Add an index for both. If

Re: Need help for performance tuning with Mysql

2012-05-24 Thread Yu Watanabe
Johnny Thank you for the reply. Second, make sure your Innodb buffer pool is allocating as much ram as possible. I'd even go as far as adding another 8gb of ram to the server. The buffer pool setting is going to give you the best performance increase. The problem is mainly on MyISAM engine.

Architectural Help

2012-05-24 Thread Anupam Karmarkar
Hi All, I need architectural help for our requirement, We have nearly 50 data centre through out different cities from these data center application connect to central database server currently, there are conectivity and nework flcutions issues for different data center, so we comeup with

Re: Architectural Help

2012-05-24 Thread Ananda Kumar
is the central database server just ONE server, to which all your 50 data center app connects On Thu, May 24, 2012 at 2:47 PM, Anupam Karmarkar sb_akarmar...@yahoo.comwrote: Hi All, I need architectural help for our requirement, We have nearly 50 data centre through out different cities

RE: Architectural Help

2012-05-24 Thread Nigel Wood
A few questions: which is more or a problem: network outages, network capacity or query latency? When you say near real-time do you need transactional consistent view on all 49 servers or can some lag be tolerated? Can any one of the 49 local servers potentially update/delete the same rows or

Re: Architectural Help

2012-05-24 Thread Anupam Karmarkar
Dear Nigel, Thank for reply.. See my comments below --Anupam From: Nigel Wood nw...@plus.net To: Anupam Karmarkar sb_akarmar...@yahoo.com; mysql@lists.mysql.com mysql@lists.mysql.com Sent: Thursday, 24 May 2012 3:35 PM Subject: RE: Architectural Help A

RE: large temp files created by mysql

2012-05-24 Thread Rick James
Maybe. 1. The Rows is approximate, so you could over-shoot or under-shoot the end of the table. 2. OFFSET (limit $r,1) still has to scan $r rows. 3. SELECT * with an OFFSET will read the entire rows. SELECT `foo`, where `foo` is indexed, but not the InnoDB PRIMARY KEY, will scan only the

RE: large temp files created by mysql

2012-05-24 Thread Luis Daniel Lucio Quiroz
For my propouses aprox is fine. I guess for others it doesnt El may 24, 2012 9:59 a.m., Rick James rja...@yahoo-inc.com escribió: Maybe. 1. The Rows is approximate, so you could over-shoot or under-shoot the end of the table. 2. OFFSET (limit $r,1) still has to scan $r rows. 3. SELECT *

RE: Need help for performance tuning with Mysql

2012-05-24 Thread Rick James
Thanks. I got tired of answering the same questions about buffer_pool and key_buffer over and over on forums.mysql.com; now I just point people at that page. INT(1) and INT(50) are identical -- and take 4 bytes. See TINYINT, BIGINT, etc. Also, UNSIGNED is probably wanted in more places than

RE: Architectural Help

2012-05-24 Thread Rick James
I deal with dozens of systems, all doing cross-country or cross-ocean replication. The only viable approach (that we have deployed in production) is * Dual-master, single writer -- That is, all 49 clients write to one machine * The two masters are geographically separate. * Failover involves